KR100336875B1 - Apparatus and method for generating pulse ion beam in electron beam deposition equipment - Google Patents

Abstract

PURPOSE: An apparatus and a method for generating a pulse ion beam in electron beam deposition equipment are provided to neutralize a substrate and optimize a state of the substrate by applying a pulse type anode voltage to an anode. CONSTITUTION: A pulse ion beam generator(1) is formed with an anode(10), a cathode(20), and a magnet(30). A substrate(40) is connected to a chamber ground(50). The pulse ion beam generator(1) and the substrate(40) are installed in the inside of a vacuum chamber(60). The anode(10) is used for striking accelerated Ar ions on the substrate(40). The anode(10) is connected to an emitter of a switching transistor(70). A pulse signal generator(80) is connected to a base of the switching transistor(70) in order to apply an RF pulse signal. An anode power supply(90) is connected to a collector of the switching transistor(70). The substrate(40) and the chamber ground(50) are connected to a negative terminal of the anode power supply(90) through a resistor(R10). The cathode(20) and a current meter(110) are connected to a down transformer(100). An intermediate tap of the second side of the down transformer(100) is connected to the collector of the switching transistor(70) through a current meter(110A), a rectifier(120), and a resistor(R20). A mass flow controller(130) is inserted into a supply tube(135).

Description

Pulse ion beam generator for electron beam deposition apparatus and method

The present invention relates to a pulse ion beam generator for electron beam deposition apparatus and a method thereof, in particular to neutralize the substrate (base material) in an optimal state by the application of a pulsed anode voltage, to prevent overheating of the anode and to generate a high energy ion beam End-hole type pulse ion beam generator and method for electron beam evaporation apparatus which enables metal, oxide, compound and the like to be coated on glass or low melting point material with high adhesion and excellent optical properties. It is about.

In general, optical systems such as an anti-reflective coating of a camera lens, a high-reflective coating of a mirror resonator for a laser resonator, a metal coating for a bandpass filter or an interference filter, etc., are required to manufacture functional optical products having optimal optical properties required for each field.

These functional optical components are made of single metals such as Cr, Al, Cu, Ag, etc., oxides such as Al ₂ O ₃ , SiO ₂ , TiO ₂ , ZnO ₂ , or compounds such as TiN, Si ₃ N ₄ , MgF ₂ . It is completed by single or multiple coatings on glass or acrylic in nm (1 nm-10 ⁹ m) units.

Metal coating mainly uses electron beam evaporation equipment or sputter equipment, and the characteristics of the thin film are clearly changed according to the composition and coating conditions of the equipment. If the optimum equipment composition and process conditions cannot be determined, the adhesion of the thin film is weak or Not only does the optical characteristic change depending on the external environment, but the electrical / optical characteristics such as refractive index, conductivity, transmittance, and reflectance are not inherent in the material, resulting in deterioration.

In the conventional electron beam deposition, it is necessary to apply high energy to the source material to be deposited so that the substrate is raised to a bondable temperature so that the vaporized source material is easily deposited when deposited on a substrate such as metal, glass or acrylic. need.

However, in the case of using a substrate such as acrylic or glass, there is a limit to raising the temperature of the substrate. Therefore, a method of activating the substrate by colliding the accelerated high energy ion beam with the substrate is adopted.

This ion beam activation method excites Ar gas, which is a kind of inert gas, by the hot electrons generated by heating the cathode, and the repulsive force acts according to the positive voltage applied to the ionized Ar + to the anode, so that the high energy ion beam hits the substrate. The substrate surface is excited by being rolled up.

However, when the ion beam activation method is used, a phenomenon occurs in which Ar + ions collide with the substrate over time, thereby causing the substrate to be posited. Therefore, the most important problem in the case of metal coating is the electric neutralization of the base material (substrate) and the control of ion energy. That is, in order to electrically neutralize the protonation of the base material by the ion beam during the deposition coating, electrons from the cathode must be moved toward the base material, which is difficult to completely neutralize due to the secondary current overflow phenomenon. Conventionally, in order to solve this problem, it is possible to improve the neutralization of the base material by adjusting the amount of the reaction gas and the Ar gas, but this causes a problem in controlling the composition ratio of the process vacuum and the coating thin film.

In addition, when it is difficult to increase the process temperature for activation of the bond, such as acrylic or polymer film, the energy of the ion beam should be increased, but the anode voltage V1 applied to the anode is constant as shown in FIG. 1. Therefore, there is a problem that it is impossible to apply the anode voltage of DC 200V or more due to overheating with time.

On the other hand, if Kaufman type ion gun is used, it is possible to increase ion energy up to 2000eV, but it is not suitable for mass production due to the limited current density of ion and difficulty in manufacturing and maintenance.

On the other hand, the above-mentioned end-hole type electron guns are widely used, which are about three times larger than the Kaufmann type, are simple to manufacture, and have high ion beam divergence. The disadvantage is low energy.

In an effort to solve these problems, researches are being conducted to solve the neutralization problem of the base metal by applying an RF coil or installing a neutralizing electron gun separately to increase the ionization rate of the gas. The problem and the increase in ion energy were not solved at the same time.

Accordingly, the present invention has been made in view of the problems of the prior art, and its object is to neutralize the substrate (base material) in an optimal state by the application of a pulsed anode voltage and to prevent overheating of the anode and to generate a high energy ion beam. Accordingly, the present invention provides an end-flow pulsed ion beam generator for an electron beam deposition apparatus and a method for coating a thin film having high adhesion and optical properties on a glass or a low melting point material to a metal or an oxide.

1 is a waveform diagram of an anode voltage applied to an anode of a conventional pulsed ion beam generator;

2 is a circuit diagram of a pulsed ion beam generator for an electron beam deposition apparatus according to the present invention;

3 is a waveform diagram of an anode voltage applied to an anode of a pulsed ion beam generator according to the present invention.

* Explanation of Signs of Major Parts of Drawings *

One ; Ion beam generator 5; Deposition Source

10; Anode 20; Cathode

30; Magnet 40; Board

50; Chamber ground 60; Vacuum chamber

70; Switching transistor 80: pulse signal generator

90; Anode power supply 100; Transformer

110,110A; Ammeter 120; Rectifier

130; MFC 135; Supply pipe

In order to achieve the above object, the present invention provides an ion beam generator of an electron beam deposition apparatus for depositing a source material on a substrate, comprising: pulse signal generating means for generating a pulse signal of which pulse width is adjustable; A switching transistor for outputting a high voltage pulse type voltage signal upon application, a cathode for emitting hot electrons by heating, an Ar gas supply means for supplying Ar gas ionized by the emitted hot electrons, and the switching transistor An anode for sucking the hot electrons and repulsing the ionized Ar ions in a first period connected to the output of the pulsed voltage signal and being positively accelerated by the Ar ions accelerated in the first period. The emitted hot electrons may be transferred to the substrate during a second period in which the voltage of the pulsed voltage signal is It provides an ion beam generated in the electron beam vapor deposition apparatus device, comprising a step of using neutralized.

In addition, according to another aspect of the invention, the step of activating the substrate by ionizing the Ar gas by the hot electrons emitted from the cathode during the first period when the pulsed voltage is applied to the anode and at the same time by repulsing the ionized Ar ions; And neutralizing the substrate positively formed by the Ar ions using the emitted hot electrons during a second period in which the voltage of the pulsed voltage signal is not applied. to provide.

As described above, in the present invention, by applying a pulsed voltage to the anode, the substrate can be neutralized in an optimal state, and 400 eV is prevented from being heated by controlling the width of the pulse voltage supplied from the pulse wave generator. It is possible to generate ion beams with high energy, which can be deposited on any base material including glass, low melting point materials such as acrylic and polymer films, and can improve the mobility of molecules and increase the size of equipment. This high and optical / physical property shows excellent properties.

(Example)

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a waveform diagram of an anode voltage applied to an anode of a conventional pulsed ion beam generator, and FIG. 2 is a circuit diagram of an end hall type pulsed ion beam generator for an electron beam deposition apparatus according to the present invention. 3 is a waveform diagram of an anode voltage applied to an anode of a pulsed ion beam generator according to the present invention.

As shown in FIG. 2, the pulsed ion beam generator 1 of the present invention is largely divided into an anode 10, a cathode 20 for emitting hot electrons by heating, and hot electrons emitted from the cathode. And a magnet 30 for applying a magnetic field to extend the average free path of hot electrons to increase the ionization rate of ionizing Ar by collision with the Ar gas supplied into the vacuum chamber. It is located inside the vacuum chamber 60 with a substrate 40 connected to 50.

An anode 10 for accelerating the ionized Ar + ions to collide with the substrate 40 is connected to an emitter of the switching transistor 70, and a high frequency pulse signal having a period of 500 Hz is applied to the base of the switching transistor 70. The pulse signal generator 80 to be applied is connected, and an anode power supply 90 for applying an anode voltage of 400V is connected to the collector of the switching transistor 70.

The substrate 40 and the chamber ground 50 are connected to the negative terminal of the anode power supply 90 through a current control resistor R10.

Meanwhile, the cathode 20 is connected to both ends of the down transformer (M) 100 for lowering the AC commercial voltage to a required voltage, and an ammeter 110 for measuring a current flowing therein is inserted into the secondary circuit. In addition, the secondary intermediate tap of the down transformer 100 is connected to the collector of the switching transistor 70 through an ammeter 110A, a rectifier 120 for rectifying alternating current to DC, and a resistor R20. Connected.

On the other hand, the pulse ion beam generator (1) includes a mass floor controller (MFC) for quantitatively supplying Ar gas supplied from the Ar gas cylinder to the supply pipe 135 connected to the electron beam generator 1 inside the vacuum chamber 60; Mass Flow Controller 130 is inserted.

The operation of the pulsed ion beam generator for an electron beam deposition apparatus according to the present invention configured as described above will be described in detail below with reference to FIG. 3.

The end hall type ion beam generator has an output diameter d of the ion beam of 110 mm, a period of a pulse signal applied to the switching transistor 70 as a control signal is 500 Hz, and an ion acceleration voltage and ion The currents are set at 400 eV and 500 mA, respectively.

First, when the cathode 20 is heated, hot electrons are emitted therefrom, and the switching transistor 70 repeatedly turns on and off as a high frequency pulse signal having a period of 500 Hz is applied from the pulse signal generator 80 to the base. Done. As a result, a pulse signal having a magnitude of 400 V is applied to the anode 10 connected to the emitter as shown in FIG. 3.

In this case, during the period T1 in which the pulse signal is in a positive (+) 400V state, the emitted hot electrons move toward the anode 10, and collision with Ar gas injected into the device occurs. Thus, neutral Ar atoms are excited by electrons and ionized into Ar + ions.

In this case, the ionized Ar + ions are opposed to the electrons (e−) and are accelerated by the positive (+) 400V voltage applied to the anode and collide with the substrate 40 installed opposite to the anode 10, and as a result, the substrate 40 Is activated.

In this case, the deposition material evaporated from the deposition material source 5 installed to face the substrate 40 is blown off and deposited on the substrate 40.

Thereafter, in the period T2 when the voltage of the pulse signal applied to the anode 10 is zero, the hot electrons emitted to the cathode 20 are not directed to the anode 10 but are posited toward the substrate 40 that is positive due to the collision of Ar + ions. The substrate 40 is neutralized.

In this case, since the application period T1 of the pulse signal applied to the anode 10 can be controlled by adjusting the width of the control pulse applied to the base of the switching transistor 70, the activation of the substrate 40 and the substrate are controlled. Neutralization to an optimal state can be easily achieved, and according to the present invention, since the voltage applied to the anode 10 is a pulse wave applied at a constant period, the anode 10 has a high energy of 400 eV or more while preventing heating of the anode 10. The ion beam can be generated.

ZnO ₂ , Al ₂ O ₃ , an anti-reflective thin film layer applied to an optical lens, an electromagnetic shielding filter, etc. is sequentially applied to a polycarbonate substrate having a low melting point using an electron beam deposition apparatus having a pulse ion beam generator according to the present invention as described above. It could be obtained by multiple coating of SiO ₂ .

In this case, the coating process conditions are the initial vacuum degree 2 × 10 ^-5 Torr, the Ar gas flow rate is 110sccm, the heating temperature of the substrate is set to 80 ℃, the anode voltage of the ion beam of the DC type prior art and the pulse type of the present invention The coating was performed by applying 180V and 350V respectively.

Thus, the reflectance of the multiple coating film deposited on the substrate was 0.48 in the conventional method, but the antireflective coating film of 0.35 in which the reflectance was greatly reduced was obtained in the method of the present invention.

In this case, the adhesion between the coated thin film and the substrate (base material) also appears to be excellent, indicating that the density of the thin film is similar to the bulk due to the improvement of the ion beam energy.

As described above, in the present invention, the neutralization problem of the substrate was solved by controlling the voltage application width of the pulse, and the overheating problem of the anode (anode) was also solved by applying the pulse wave, thereby making it possible to generate an ion beam having an energy of 400 eV or more. .

This can improve the mobility of molecules, etc., as well as increase the size of the equipment. In addition, glass can be coated on any base material including low melting materials such as acrylic and polymer films, and special functional optical products such as mirrors, electromagnetic shielding filters, and security filters with semi-permanent and excellent optical and electrical properties can be produced. .

As described above, in the present invention, by applying a pulsed voltage to the anode, the substrate can be neutralized in an optimal state, and 400 eV is prevented from being heated by controlling the width of the pulse voltage supplied from the pulse wave generator. It is possible to generate ion beams with high energy, which can be deposited on any base material including glass, low melting point materials such as acrylic and polymer films, and can improve the mobility of molecules and increase the size of equipment. This high and optical / physical property shows excellent properties.

In the above, the present invention has been illustrated and described with reference to specific preferred embodiments, but the present invention is not limited to the above-described embodiments and is not limited to the spirit of the present invention. Various changes and modifications can be made by those who have

Claims (2)

An ion beam generator of an electron beam evaporation apparatus for depositing a source material on a substrate, Pulse signal generating means for generating a pulse signal capable of adjusting the pulse width; A switching transistor for outputting a high voltage pulse type voltage signal in response to the application of the pulse signal; A cathode for emitting hot electrons by heating, Ar gas supply means for supplying Ar gas ionized by the emitted hot electrons, An anode for sucking the hot electrons and repulsing the ionized Ar ions in a first period connected to an output of the switching transistor and applying a pulsed voltage signal, The ion beam of the electron beam deposition apparatus is neutralized by the emitted hot electrons during a second period in which the voltage of the pulsed voltage signal is not applied. Generator. Activating the substrate by ionizing Ar gas by the hot electrons emitted from the cathode during the first period of applying the pulsed voltage to the anode and simultaneously accelerating the ionized Ar ions; And neutralizing the substrate, which is positively formed by the Ar ions, with the emitted hot electrons during a second period in which the voltage of the pulsed voltage signal is not applied.

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